The subject of this invention is a video on demand (VoD) architecture being able to operate or supported in a peer-to-peer manner.
VoD services are attractive since they provide great control to users over when and what to watch: In the VoD service the time elapsed between the staring of the demanded video's playback and the video's demand is necessarily very short. A VoD service should also allow common Video recording and playback operations such as pause, rewind or fast forward.
VoD offerings not only need to provide high reliability and flexibility for the customers but providing VoD services is also challenging in the provider network due to the high bandwidth and real-time playback requirements. Widespread deployment of VoD services, especially providing high-definition video quality threatens with extremely high load during peak hours, especially near the VoD servers where the demands aggregate.
While VoD services gain foothold, one can observe a continuously improving performance in the network segments close to the subscribers from at least two different aspects. Firstly, capacities in the access and aggregation networks are getting higher and higher as optical transmission is moving closer and closer to subscribers. For instance, there are providers already offering Fibre-to-the-Home (FTTH) access to customers. Also new standards (e.g. DSM) will offer high speed access even through twisted pair access. Secondly, one can observe an ever increasing storage capacity in the customer premises as the price-per-bit of hard-drives is decreasing. Customers, therefore, can store several movies, hundreds of images or music files on their disks, be it a PC or a set top box (STB).
Observing these trends it is quite natural to think about how a VoD operator could benefit from the free storage capacity at the customer premises and the potentially free bandwidth in the access and aggregation networks.
The immense success of peer-to-peer (P2P) file sharing in the Internet points out the basic concept of a potential VoD architecture, where the STB of a customer A, having enough storage capacity to store already downloaded movies long after it has been viewed, can upload videos to a customer B if B wants to watch a video that, at least partially, is available in A's storage. Building on such a technique and utilising the unused capacities in the access, the operator can offload its central service node and its backbone network as a decreased amount of content has to be downloaded from the central VoD servers.
As uplink capacities of the customer premises increase, by exploiting the potential of peer-to-peer uploads, more bandwidth can be spared at the backbone. This may result in net gain for the VoD service provider for instance in case of rented transport. Therefore, such models come to be more relevant as high-speed access technologies are getting deployed. It is straightforward to see that as much capacity can be spared at the upper part of the network as much free uplink capacity the peer-to-peer approach can be utilised in the bottom part.